In recent years a remarkable progress has been attained in performance improvement of electronic equipment. In particular, functional capabilities and speed of CPU or chip sets (referred to hereinbelow as “heat-generating body”) which are heat generation sources located inside the electronic equipment have been continuously increasing. On the other hand, miniaturization and thickness reduction of electronic equipment, in particular, space-saving electronic equipment such as notebook personal computers (referred to hereinbelow as “notebook PC”) are also strongly required. With this in view, rapid increase in heat generation per unit volume in electronic equipment can be anticipated. As a result, there is a risk of temperature increasing in the electronic equipment and, for example, the CPU exploding or fracturing under the effect of heat. For this reason, it is necessary to cool the heat-generating bodies with efficiency higher than that of the conventional cooling methods in order to prevent the temperature of electronic equipment from rising.
There is a technology for cooling a heat-generating body whereby the heat recovered from the heat-generating body is dissipated from a heat-dissipating section provided on the display section side by transporting a cooling liquid as a heat transfer medium to the display section side of the case. This technology is disclosed in Japanese Patent Application Laid-open No. 2002-182797.
With the technology disclosed in Japanese Patent Application Laid-open No. 2002-182797, the heat is recovered by the cooling liquid from the heat-generating body by connecting a tube filled with the cooling liquid to the heat-generating body via a heat-receiving head, and the recovered heat is dissipated by passing the tube between the display section case and the liquid-crystal display panel of the display section. As a result, dissipation of heat locally generated inside the case can be conducted from a wider range by using the display section case.
However, with such a technology, because spontaneous cooling (spontaneous heat dissipation) is used for heat dissipation, only a limited cooling efficiency can be attained. Furthermore, because the size of the case has to be increased to increase the heat dissipation quantity, the requirements relating to miniaturization and thickness reduction of equipment cannot be fully met. Moreover, because heat dissipation from the case is used, the increase in the temperature of the case cannot be avoided and the user feels uncomfortable when touching the case.
Japanese Patent Application Laid-open No. 11-177264 discloses a cooling technology similar to that described in Japanese Patent Application Laid-open No. 2002-182797 and has similar drawbacks.
Japanese Patent Application Laid-open No. 2002-163041 discloses a technology whereby diffusion of heat in the heat-dissipating section provided on the display section side is forcibly conducted with a fan as a technology for increasing the cooling effect, while inhibiting the increase in size.
However, though the cooling technology of Japanese Patent Application Laid-open No. 2002-163041 provides for forced cooling with a fan, no special thermal insulation treatment is carried out with respect to the display section case. Therefore, heat is unavoidably transferred to the display section case in an amount equivalent to that during heat dissipation. Therefore, the temperature of the display section case rises and the user feels uncomfortable when touching the case.
The technology using forcible cooling with a fan is also described in Japanese Patent Applications Laid-open No. 11-87961 and 10-213370. The cooling technology described in those open publications does not involve thermal insulation treatment of the case in the heat-dissipating section, and if the quantity of heat that has to be dissipated increases, the temperature of the case rises and the user always feels uncomfortable when touching the case.